/Engine/Source/Developer/AutomationDriver/Public/IAutomationDriver.h
This is a non-blocking call and doesn't invoke the locator until some action is performed on the element. You will need to invoke the Exists() method on the element to confirm the elements existence if that is what you want to do.
a driver element representing a single element located by the specified locator
[TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [IAsyncDriverElement](API\Developer\AutomationDriver\IAsyncDriverElement), ESPMode::ThreadSafe > FindElement ( const [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [IElementLocator](API\Developer\AutomationDriver\IElementLocator), ESPMode::ThreadSafe > & ElementLocator )